Country dance displays are rather out of fashion these days. There are a limited number of strongly dance oriented festivals that might be interested. Eastbourne is probably the best place to start and, hopefully, they may also be able to point you towards other suitable contacts.

Chippenham have a big dance display section. I think they give team members free season tickets and camping, but keep them so busy that they can't really use the season tickets for the events they'd like to go to beacause they are getting ready to perform somewhere else. Great festival, end of May.